Question

Review Constants Periodic Table Part A A A beaker with 2.00x10mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M student adds 5.50 mL of a 0.340 MHCl solution to the beaker. How much will the pH change? The pKof acetic acid is 4.740 Express your answer numerically to two decimal places. Use a minus ( - ) sign if the pH has decreased. View Available Hints)

a beaker with 2.00×10^2 mL of an acetic acid buffer with ph of 5.00 is sitting on a bench top. the total molarity of acid and conjugate base in this buffer is 0.100M. A student adds 5.50 mL of a 0.340M HCl solution to the beaker. how much will the pH. change? the pKa of acetic acid is 4.740

Answer 1

Volume bugger = 200 ml = 0.22 PH= 5.00 Mbuffer - '0.100 M ho. of moles (CH3COOH + CH3COON) = 0.100 M x 0.22= 0.02 mole Pka = 4.740 PH= pka + log Conj take сенз с сон 5.50 = 4.74 + log THƏToona CH3COOH log CH3COONG CHCOOH - 5.50-4.74 CHз со на = antilog (075) CH3COOH 5.744 CH3COONG = 5.7544 CH3COOH CH3 COOH + 51754U CH3COOH = 0.02 CH3COOH = 002 6 7540 = 2.95 x 10-3 mole CHgcoola = 5.7544 x 296X10-3 = 0.017ou mole no a moles of hee = 0.340 X 5.5 1.97X10 To no. of mole of CH3COOH = 2.96X10-3 +1.0 x1039.93 x 103 no. of moles of CHaTooNa 0.0174 - 0.00187 0.0151 New PH = 4.7yo tlog dio1517 0.00493 - 4.740 to.497 = 5.237 Charge in pr= 51237 515 = -0. 263